Overload motor-controlling apparatus.



A. SUNDH.

OVERLOAD MOTOR CONTROLLING APPARATUS.

APPLICATION FILED AUG.16, 1907.

1, 1 1 1,240. Patented Sept 22, 19m

jwjw '64:. 21

. UNITE STATES PATENT OFFICE.

AUGUST SUNDH, OF YONKERS. NEW YORK, ASSIGNOR TO OTIS ELEVATOR COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

States,- 're'si'dirig""at Yonkers, in "the' county of estchester and State oif "7ork,"hawe inventeda" 'hew antl useful'Improvement in Overload Motor- Comrcllifig' 'app'arauisg i which idi flfql Another object" is the prjo'i'ision Z of auto-' forape'iaunga circuit breaker of iang-e miaaed rage "of e;-

matic' means in the. or

cessire ciir'rent to the motor.

Further objects willf'ap'pear hereinafter, the norel combinations of' elements being pointed out inthe appendedfclai ns. l

The accompanying sheet ofd'rawingilliistrates diagrammatically a" simple wiring plan" whereby I 'a'cc'ornplish yarious obj t I 21" z:'Yi'.f1""'*.:'-"--i ral y p aki m th d. r' ematically starting and accelerating an'electrio motor consists'in'; series of electrically operated relays which, control a starting resistance in seriesjii'ith themnotor armature. These relays are operated'by the counterclectro-motii'e force of the .motor which ',is substantially proportional to its'speed. .A second series of electrically. operated relays controlled the first named rclayslcontrol a portioirof the motor startingresistance and depend forthe'ir operation upon a time element." Another electrically operated switch controlsva circuit breaker under certain conditions of overload or. excessive cur rent flow. v

While my system of motor control is adapted to either a direct, alternating, or pulsating current electric'rnotor, in order to make the wiring diagram as simple aspossible so that the same may readily be understood, I have hosen for purpose of illustration, a simple shunt wound direct current motor in vwhich A esignates .the motor armature, and P- the shunt field winding.

C designates a combined main line switch and circuit breaker having a switch arm 31 upon which, but insulated from it, are mounted contacts 33 and 34'. i

32 is a slot in the switch arm'31'and 37 is a compression springwhose tension may be varied by means of a set screw 38;

V v Specification of petters Patent. Patented Sept. 22, I Applicatioufiled August 16,1307. Serial No. 888,812. I

t with the core {l7 ofthe relay I."

designates an insulated handle con- 7 nected to the switch'arm' 3l'and for the purpose of manually closing theswitch. C

l designates a main line relayconiprising a'i'nagnet windmgior'solenoid 76 and core 48' wh1ch carries on an CXCQIISIOILlOf ts upper I I MYOVERLOAD Moron-CONT OLLING APPARATUS.

A triplci er lti 'isipiv oteid at 27 and is normally held [in horizontal position against a stop 28 by means of a spring 29,

which may be adjusted by a setscrew 30.

One endof this trip lever 26is inengage *mrit' withthe switch arm 31 and holds the latter in closed positionagainst tlie'.action of thespring 37. lNhen in suchclosed p-ti'sjil tion the contacts 33' and 34"areheld inlele c- "trical engagement with two fixed contacts 33 and 34respectively. The-other end of this trip lever 26is in verticalfalinement hereinafter pointed out j I 1 m8 fl XlP ld c n o switch whlch comprises a"switch'lever pivafter the latter has been opened in a manner oted at '9 and earrying'ah insulated sliding contact '10 which is adapted tomo'veove r end a Contact plate 49 which is adapted when raised by the solenoid 76 to bridge, 'or electli Cally connect Itogether,'two fixed'contacts '13 directly above and in line with it.

" The relays 1, 2, 3 and 4-, control the starting resistance F which is shown divided into four sections 68, G9, 70 and 71. The relay 1 comprises a winding 77 and magnet core 50 having ahfextension piece atits'upper end'to which is attached a contact plate 51 adapted when raised to engage fixed contacts 14. The lower end "of the core 50 carries a contact plate 52 -which' is insulated therefrom spring 5 partially counterbalances the core 50, and its connected contact plates and is capable of adjustment by means of the set screw 55. The relay 2 has a winding 78, core 59, contact plate 65, and spring 6 similar to those of relay 1 and controls the fixed contacts 15, but the lower contact plate and cooperating fixed contacts are omitted. The relay 3 controls the fixed contacts 16 and lower contacts 62 and 63 a nd is Similar to relay 1, while the relay is similar to re lay 2 and controls the fixed contacts 17; The set screws 55, 56, 57 and 58 by which the re spective springs 6,6, 7 and 8 may be ad plates 40 and 41 which a're "adapted when raised to bridge fixed contacts 18 and 19 re spectiveiy directlyaroree The lower' ehd' of each core is connected hy;a;-rod to; th e piston.

of a dash pot device 20 and 21 provided with ball check valyes;.23 ;and 2at. respecti\ ely, which latter operate in a lwellgknown' manner m n e r r spec i e "acne-p o s i more freely in afldoiyinward direction but. re-

t i 1rdirigv the moi/ ed upwardly.

I 'l he -"da'shpot rods fcarry" insulated. pieces. 82 i i iiicigigre mounted contacts AC3 iji 'adapted when raised to engagefixed n ntacts 5 vn ght (3 i-jespectivelyfi. The-relayI S ip fq ldedj f rritli magnet ,winding or s l ee d ..a min tr a d "lever-12c a dercea inic dition's'which sill-he out later, and ryhoselower s qoinnccted r od to the di li't fild e n istsimr i laiu to. th, dash used Q" it 'rr t-he relays Under "ad-rain" sanitiz ng the main line switch gr circuit lbrealterffcj is closed as she jand th'ei. positiy' aiidinegative current 85.,a d, f( t respectiy ly fjffhelciiicuibto the ri L f. ,i iiai ttli 'p i e l by wire {8151b thebrusli: ,T3;',' motor armature 'f' 1 listzittiiiQ-fisi'stahCia F andby 3 an ii;coiitat iate jt9 when the "wire 74. The "shunt nal connected at 81tothe positive wire-s5 the other; terminal is connectcd by wires 82. and 89 and 'c'oiitacts 13 when'thelatter are closed to ',tlien egatiye main 74'. It will b tic'cd that both'jhe armature and shunt tield circuits are open circuited at the contacts 13 when therelayE is not enerlgized jtojiraise the""contact plate 49 and bridge the contacts 13 The magnet windings, 77,- 78, 79', "'and 80 of the relays 1, 2, 3 and 51, respectively, are connected in" series i vith each other and one outside terminal is connected by fthe Wire 6 the brush 72. Theothe'r' outside terminal is connected to the other brush 73 b'vj the wires 86 and85. These'windin'gs' are therefore in parallel re lation to the motorarmature A.

I will now describe the operation of my motor controlling system. I V

Assuming that the main line switch C is closed as' shown, the manually operated switch D is moved to the right until the sliding c ontact 10 bridges the fixed contacts ll and 12.? This ope'ration closes a circuit through the winding of relay 3i i r d ighi ic eeg 3'.- ;n, respectively to. the main' feed wires The circuitto therein G is from the positive feed WIIG 85. win .ing of relay G, wire "91, contact 54, contact plate 52,-contact 53 and torthemegatiye feed wire 7 1 by way of relay E is in a closed circuit across the mains 85 and 74, it becomes energiz ed to raise its core 48 and thereby bridge the contacts13. .As before point-ed out, this closes the 11no and also closes a circuit through the shunt field B and the motor will start, itsicurrent being limitedin amount by tlie starting resistance F. As the motor acceleratesrnotiye forcewhich increases with thespeed. and, since the relays 1, 2,3, and 4. are connected in parallel to the motor armature they willbccome more and more energized until finally the..relay 1 will raise its core Y and connected parts thereby I short-circuiting a portion 68 of the "starting resistance "and at the. sametime open circuit-ingthe tact .54: ofrelay 1. .Since .a'l portion of the sta 1ftiflg resistance designated by 68 has been short-cireuited "the motor receives additional current from the :main lineand its crease of eonnter-eleetro-niotiye-force. More current will therefore flow inithe windings of the relays l, 2, 3 and t and the relay 2 becomessufliciently energized to raise its this contact plate israised it will bridge the contacts 15 andanot-her portion 69 of the starting resistance is short-circuitcd followed by a further increase of motor speed.

energized insuccessire order to short-circuit the remaining starting resistance and the motor rapidly assumes full speed. current from the main line flowing directly to the in circuit. The relay G will not operate when the motor is started with normal load for the reason that the dashpot 20 which is connectedto the core of the relay, retards accelerating relay 1 has operated and the circuit to the relay G is then opened at the contact 54. The relays H and I cannot operate since their windings are open-cir- The relay 1. is also open-circuited at the contact 63 as soon as the accelerating relay 3 has operated.

The foregoing description shows the oper- 12, l0 and 11, to the i'zegative feed wire 74. 70

the switch D. Now since the winding of tor circuit through the starting resistanceHF;

in speed it will generate a counter-electro-;

as the counterelectro-motive force increases. 9

n agnet winding of the relay G at the con-1 5 speed increases accompanied bya further in- ,100

core: and connected contact plate 65.= AS

In a similar manner the relays 3 and 4 armmotor armature with no starting resistance1 5 its upward movement until after the iii-SL cuited at the contacts 45 and 46 respectively.

ation of the system under normal conditions the contacts 44 and 46.

of load. Now in many places where amotor contacts; and short-circuit the starting re-' sistance ,andthe resultwillbe to merely heat the resistance.- In order to prevent this needless waste-of current and atthe same time to make it possible; for. the motor to. start the .overload, I provide the relays G and H.- The operation; ofi .thesystem in .startingwith an overload is, ,as follows Upon closing the hand switch D the relay. E will be energized asbefore and complete the motor, circuit also a circuitto theshuntfield B and winding of relay G and the latter will be energized-to sloyvly raise its ,,core- ;and connected contact; gdey-ices retarded bythe dashpot 2( As soon thecontact plate 40 bridges thecontacts .18 the first-section 68 of the star ting,- resist- .ance. short-circuited and the :motor; now

.receives additional current and :is; enabled to start itsload, As the motor accelerates, the

' .relays 1, 2, and 4 operate-successively as before, to short-circuit the entire starting resistance.- lAs soom -howev'er, ;as, the 1 relay .-;1 I operates, the relay G is open-circuited at the contact 54 and-drops backtoits original' po- .sition; -Should the motor refuse ;.;to start when the 'firstsection 68 ofthe starting, re- 2 sistance is short-circuited, the relay H Wllli receive current byiwayof thecontacts 43 and 45 which are closed-by the relay-Gt; The

winding of relay H is now connected in parallel to-the-winding of'relay G and it willslowly operate to close the contacts 19 and The contacts 19 short-circuit the section 69*01 the starting resistance, and the contacts 44 and 46 close a circuit to the Winding of the relay I connecting-the same in parallel to the relays G and H through the contacts 63 and 62, of

the relay 3. The relay I is thereforeenergized and raises its core slowly under the retarding} action of the dashpot 22. Should the motor beunable to start after the sections 68 and69 of the starting resistance have been short-circuited, the relay I will finally engage the trip lever 26 of the main line switch C and the lever will swing about the pivot 27 until-the right-hand end registers with thc'slot 32. The spring 37 is now enabled to open the switch C thereby separating the contacts 33, 33' and 34, 34 respectively, and all current supply is at once cut oil from the motor and other circuits and all the: parts return to normal positions. Should the motor start after the relays G and H have operated to short circuit the sections 68 and 69 of the starting resistance, the accelerating relays will .operate in their successive order as the motor accelerates and the windings of the relays Grand H will thereupon, become open-circuited-at the-contacts 54 and 53 of relay .1 andwillgdrop their cores. Since the circuit of ;relay;H,-i's closed bythe .relay G and-the ,circuit of relay- I is closed by the relay. H, it follows that each of these relays will: operate inl a predeter- 1 .niinediorder since the circuit of? one relay depends upon the previous i operation; of its companion relay. Inthe event of therela-y 1 refusing to operate and the relays G and H .close their contacts, thusenergizingathe y- 1; thmc el ra ingjrel yzfim ll gperat to open the circuit to the relay;I- atithe'fcom tacts 63 and 62, and the .-m'ain;line switch C, consequently "will nOt' be tripped to open the inoton circuit.-

Fro the foregoing readily beseen that. the-motor is effectually safeguarded from long continued; flow of excessive starting current, for While it; may be necessary in order to start ;anove rl,oad:to gi ve themotor current greatly excess of aits .-norma l.- starting current, it is neithergsafe nor desirable to allowthis excessivehcurrent to flowforany great length oftime The relay I maybeadjusted to gtrip; the main' line switch after a .certaindnterval oftimehas c assed-- p i g p nit e adju n of the dashpot 22,.which maybe-providedwith a valve or air cock to regulatethe admission of air or other fluid under the dashpot pistonhin a-well-knownwa'y. f zThe accelerating relaysg 1, 2, 3 .and 4 are adjusted so that they will operate successiyely. in a predetermined order. Thismay be done by varying the tension of the springs 5, 6, 7 and 8 respectively or by varying the distance which the cores of the relays have to travel in order to close their. respective contacts.

l/Vhile'I have shown but four accelerating relays and a corresponding numberof-sections into which the starting resistance is divided, the number of relays and resistance sections may be more or less than four, de pending to a large extent upon the duty and capacityof the motor. Where a compound motorisused I frequently arrange the accelerating relays to first shortcircuit the starting resistance and then short-circuit the series field in one or more steps. Any desired number of relays such as G and H may be used as I do not desire to limit myself to any particular number, the principle of operation being the same regardless of the number of relays connected in circuit.

What I claim as new and desire to protect by Letters Patent of the United States lSZ 1. The combination of a motor having a sectional starting resistance, a source of electrio. current, means controlled by thecounter-electro-motive force of the motor for sue eessively cutting out the sections or resist ance, and additional means for cutting out said resistance upon failure of said firstnamed 'means'to operate.

2. Theicomhination of an electric motor, havinga starting resistance, a source of current-supply for the motor, a circuit con nected across the brushes of the motor, electromagnetic means in said circuit for-controllingthe starting resistance,- and additional means dependent upon the load to control the resistance. 33 Th'e comhination of an electric motor having a starting resistance, means for automatic ally cutting out a portion of said re- -sistance as the speed of the armature increases, and additional means for cutting out a portion of the starting resistance "upon failure of the first means to operate.

-4-.'The combinationof anfelectric motor, having a sectional starting resistance, automatic means for cutting out a portion of the resistance as the speed of the armature in creases, and additional means for cutting out s'aidportion of the resistance upon failure of' the'first means to operate. i

"The combination of an electric motor having a sectional starting resistance, a p'lu :rality of electromagnets operative succes' sively to cut out the sections of resistanc'e'as; the armature speed increases, and means for cutting out said sections upon failure of the electromagnets to operate.

6. he combination of an electric motor having a sectional starting resistance,a plurality of electromagnets operative succes-Z sivelvto shortcircuit the sections of the starting resistance, and additional electromagnets' operative to cut out the sections of starting resistance upon the failure of the first electromagncts to operate.

'4"; The comhination of an electric motor having a starting resistance, a plurality of electromagnets operative successively to cut out portions of said resistance, additional electromagnets operative successively to cut out portions of thestarting resistance upon failure of the first named electromagnets to operate, and means for retarding the operation of. said additional electromagnets.

8. The combination of an electric motor, a sectional starting resistance therefor, a circuit connected across the motor armature, a pluralit; of electromagnets in said circuit operative successively as the current through said circuit increases, means operated by the electromagnets for successively cutting out the sections of the starting resistance, and retarded mechanism for cutting out a por tion of said resistance upon failure of said electromagnets to operate within a predetermined time limit.

9. The combination of an electric motor,

a sectional startingresistance therefor, 21 circuit'in' parallel With'the motor armature, a 'plurality'of electromagnets in said circuit, operati ve successively as 'the' current through said-circuitincreases, means operated by the electror'ha-gnets for successively cutting out the sectionsofstarting resistance, and means for cutting out a:por'tion of the starting re 'sistance' up'onfailure o'f' saidjelectromagnets tolop'eratel 5 1? 105 '-I he"comb ihjation of an el ectric motor,

a starting -resistatice', a=circiiit I in parallel withthe motor-armature, a plurality of electrom agnets in' said circuit, operative successively'as the current" tl i'rough said circuit increases, meansoperated hf {the electromagnets for successively cutting out portions of the s'tart'ing i resistance, a retarded electromagnet,-= and means operated thereby to" cut out a portion of; the startingresistance upon failure of the other ele'ct-romagnets to opcrate;- l1.;1- he*"comhinati0n of an electric motor, a starting resi tame, a circuit in parallel ivith theiinotor. rmatur,a' "series of electro- -magne1ts -in said circuit, operative succes- 'sivelyfa s the {current through said circuit increases, means operated by the electromagnets for successi vely cutting out portions'of 'the starting r's'istance, a' second series of electromagnetsop'erative successively, means op'erated' by the second series of electromagnets for cutti1 1g out portions of the starting resistance' upon failure of the first series of magnets to"6perate,means for retarding the "operation-10f the second series of electromaghe'ts,"

-12'-.- The eombin on of a motor, a starting resistance, anelectroma'gnet, means operated thereby-for cutting out a portion of the resistance, a second electromagnet, means operated thereby for cutting'outa portion of the resistance upon failure of the first electro'magnet to operate, means for opening the circuit through the second electromagnet when the first operates; and means for retarding't'ne operation of'the second electromagnet to give the first one time to operate.

13. The combination of an electric motor, a starting resistance. a series of electromagnets arranged and adapted to be successively operated, means operated by the magnets for successively short-circuiting portions of the resistance, a second series of electromagnets, means for causing them to operate successively upon failure of the first electromagnets to operate, means operated by said second series of magnets for successively short-circuiting portions of the starting re .istance, means operated by the first series of electmmagnets to render the second series inoperative, and means for retarding the operation of the second series to give the first series time to operate.

l t. The combination of 'an electric motor, starting resistance, an electriccircuit in parallel Withthe armature of the motor, a plurality of electromagnets operative with current of different strength and havingtheir windings in said circuit, said electromagnets being arranged to operate successively as the speed of the armature increases and thereby increases the counter-electromofifet force, means o erated" by said electi oina'g nets for successively short-circuiting portions of the starting resistance, and retarded means independent of the speed of the arma ture for short circuiting portions of the starting resistance when the electromagnets fail to operate.

15. The combination of a motor, automatic means for controlling the acceleration of the motor, a circuit breaker operative upon failure of said means to operate, and means controlled by the counter-electro-motive force of the motor for preventing the operation of the circuit breaker when said controlling means operates.

16. The combination of an electric motor, a source of current therefor, a starting resistance in the motor circuit, a device to automatically open the motor circuit upon failure of the motor to start when its circuit has been closed, and electro-responsive means controlling said resistance dependent upon the counter-electro-motive force developed by the motor for normally preventing the operation of said device.

17. The combination of a motor, a source of current, a starting resistance in the motor circuit, retarded means for automatically opening the motor circuit upon failure of the motor to start within a predetermined time after its circuit is closed, and electroresponsive means controlling said resistance dependent upon the operation and develop ment of a certain speed of the motor for preventing the operation of said retarded means.

18. The combination of an electric motor, a starting resistance therefor, a source of current, means for opening the motor circuit upon failure of the motor to develop a given speed within a given time after the motor circuit has been closed and before said resistance has been cut out of the motor circuit, and an electro-responsive device for rendering said means inoperative when the motor develops said speed, said device being dependent for its operation upon the motor developing said speed.

19. The combination of a motor, a source of electric current for the motor, a starting resistance in the motor circuit, a circuit breaker, retarded means for operating the circuit breaker in a predetermined time after the motor circuit is closed and before the said resistance has been cutiout of the mo-- torv ,circuit, :and .electro-responsivemeans controlled by the speed of the motor for rendering said retarded means inoperative.

20. The combination of a motor, a source of currentn supply,an. automatic isv'vitch in the.motor circuit, a starting resistance, automatic electromagnet relays for cutting outres a c ,irhent e..metqrehesjstarted; retarded means for opening the automatic switch, and means operated by the magnets of said relays for rendering the said'switchopening means inoperative.

21. The combination of a motor, a source of current supply, a starting resistance, a circuit in parallel with the motor armature, an electromagnet having its Winding in said circuit and operative when the motor has developed a predetermined counter-electro-motive force, means operated by said electromagnet to short-circuit the starting resistance, a circuit breaker in the motor circuit, a second electromagnet and means for causing it to operate when the circuit through the motor is closed, means operated thereby for short-circuiting the starting resistance, means also controlled by said second electromagnet for opening the circuit breaker, means for retarding the operation of the second electromagnet, and means operative upon the operation of the first-electromagnet to render the second electromagnet inoperative, and thus prevent the opening of the circuit-breaker.

22. The combination of an electric motor, a starting resistance, a circuit in parallel with the motor, a plurality of electromagnets in said circuit operative successively as the speed of the motor increases, means operated by the electromagncts for successively cutting out portions of the starting resistance, a second series of electromagnets, the first magnet of said series having its winding in a circuit which is closed when the circuit through the motor is closed, means operated by each of said second series of electromagnets for closing a circuit through the succeeding magnet of the series, to operate said magnets successively, means operated by each of said second series of electromagnets for shortcircuiting a portion of the starting resistance, means operated by the first series of magnets for opening the circuit through the second series and rendering them inoperative, means for retarding the operation of the electromagnets in the second series, a circuit breaker in the motor circuit, means operated by the last of the second series of electromagnets for causing the circuit breaker to operate, and means for retarding the operation of the circuit breaker.

23. The combination with an electric motor and accelerating apparatus therefor, of nameto this specification in the presence of .meanscontrolled by the -c0unter-electr0motwo subscribing witnesses.

tiveforceiof-the motor foroperating said T accelerating apparatusf-nndadditional AUGUST SULDH 5 means for operating said apparatus upon the \Vit'nesses:

failure of first named means to operate. CHAS. M. NISSEN,

In testimony.- whereof, :I have signed my si LLFRED C. BECHET.

copi sof this indent 'maly'ime febte ined for 'fi v e Cents each, by addressing the Commissioner of Patents, Weshington, D. C. 

